. . . "Definition: The biological source (organism, tissue or cell type) of an Entity. \n\nUsage: Some entities are considered source-neutral (e.g. small molecules), and the biological source of others can be deduced from their constituentss (e.g. complex, pathway).\n\nInstances: HeLa cells, Homo sapiens, and mouse liver tissue."^^ . "Definition: The biological source (organism, tissue or cell type) of an Entity. \n\nUsage: Some entities are considered source-neutral (e.g. small molecules), and the biological source of others can be deduced from their constituentss (e.g. complex, pathway).\n\nInstances: HeLa cells, Homo sapiens, and mouse liver tissue."^^ . "Definition: The biological source (organism, tissue or cell type) of an Entity. \n\nUsage: Some entities are considered source-neutral (e.g. small molecules), and the biological source of others can be deduced from their constituentss (e.g. complex, pathway).\n\nInstances: HeLa cells, Homo sapiens, and mouse liver tissue."^^ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .